Pressure ventilating system



April 16, 1940. c. o. BERGsTRoM PRESSURE VENTILATING SYSTEM Filed July22, 1958 2 Sheets-Sheet l INVENTOR. 6fm/ O. BEGsT/eoM ATTORNEY.

' April 16, l940- yc. o. BERGsTRoM 2,197,740

I PRESSURE VENTILATING SYSTEM Filed July 22, 1958 2 Sheets-Sheet 2INVEA'TOR. Cafe/ O. BERGST/eorf/ A TTORN E Y.

Patented Apr. 16, 1940 PRESSURE VENTILATING SYSTEM Carl O. Bergstrom,Boston, Mass., assignor to B. F. Sturtevant Company, Boston, Mass.

Application July 22, 1938, Serial No. 220,681

3 Claims.

This invention relates to Ventilating systems and relates moreparticularly to pressure ventilating systems for passenger vehicles.

Air cooling systems utilizing refrigeration for passenger vehicles suchas railway passenger cars are relatively expensive to purchase and 'tooperate; they add considerable ,"dead weight to the cars which has to becarried during all of the time even though the equipment is used for lcooling purposes but a relatively small portion of the time, and theequipment requires a great deal of servicing for maintaining it inoperating condition. l.

It has been proposed heretofore to dispense with refrigeration forcooling railway passenger cars and to affect cooling by circulatinglarge volumes of outdoor air through the cars but in such priorproposals propeller ians were to be used for blowing the air directlyinto the'passenger space.

This invention provides a pressure Ventilating system utilizing aplurality of centrifugal fans with Wheels mounted just below theceilingand communicating through openings in the ceiling with ltered outdoorair. The fan wheels ex'- tend in alignment down along the'longitudinalcenter of the car and-blow'the outdoor air in substantially Vhorizontalstreams into the car. The outdoor air displacesf the heated air throughgravity and pressure and thus enters the passenger space, and an equalvolume of `air from the passenger space is exhausted from the car.

In one embodiment of the invention, a plurality of ducts extendcrosswise the car with outdoor air inlets in both ends of each duct andeac-h centrifugal fan receives air through one of the transverse ducts.the car pass the exhaust air from Athe car over and around the ducts toremove heated air from ceiling with outdoor air for cooling theypassenger space with relatively large volumes of outdoor air.

Other objects of the invention will be apparent from the drawings andthe following description.

The invention will now be explained with reference to the drawings, ofwhich: Fig, 1 is a plan view looking downwardly with Exhaust outlets ineach end of portions cut away and other portions in dottedy outline, ofa railway car embodying this invention;

Fig. 2 is an elevation view with a portion in section, of the car ofFig. 1;

Fig. 3 is a sectional view along the lines 3 3 of Fig. 1, and

Fig. 4 is a'sectional view'along the lines 4 4 of.

Fig.l 1.

In the embodiment of the invention illustrated, the plurality of ducts 6extend crosswise the car between the ceiling 'l and roof 8. Each duct 6is spaced fromthe roof to provide space for air to flow between theducts and the roof.

Each of the ducts 6 as shown most clearly by Fig.v 3, extends throughthe sides 9 of the car and communicates' through the ventilator hoodsl!) with outdoor air. of the hoods serve to clean the air entering theducts.

The frames `I2 containing the balanced dempers I3 extend across theinlets to the ducts 6 and the dampers are adjusted to open for entry ofoutdoor air but to close to prevent air from being exhaustedtherebetween. If these dampers were not provided, a cross wind couldblow through the ducts l,v interfering-with' the operation ofthe fansand causing undesirable noise. d

`In the center of each of the ducts (i is mounted the centrifugal fanindicated generally by I4 and having the motor I5 mounted in the duct 6above the ceiling 1, and having its fan wheel (not shown) and thedeflector housing I6 surrounding the fan wheel, mounted below theceiling.

The lower side of the duct is apertured and the ceiling 'I is aperturedat 5 varound the fan shaft to permit the passage of air from the duct 6to the fan wheel. The details of the centrifugal fan utilized aredisclosed in my copending applicatiomserial No. 166,803,1iled October 1,1937. vThe airexhaust outlets l1 are placed inthe ceiling 'I at each endofthe passenger space and serve to pass the airexhausted from thepassengerl space, into the space between the ceiling 1 and roof 8.

yThe roof exhaust outlets I8 are arranged adjacent the roof, one in eachside of the car, and

the outlet I8 in one side of the car'is placed to oneside of thelongitudinal center of the car and the other outlet I8 is arranged tothe other side of the longitudinal center of the car. eliminators I9prevent the entry of rain Water and the' balanced dampers 20 prevent theentry The filters II in theentranceA The ini

of outdoor air into the outlets I8. These outlets f the outlets l?, fromthe roof space after the air has passed over and in contact with theducts 6.

In operation the centrifugal fans I4 draw outdoor air through thefilters il. the dampers i3 and ducts S and through apertures in thelower sides of the ducts and in the ceiling and this outdoor air isforced in substantially horizontal, laminated streams circumferentiallyaround the fan wheels. The horizontal delectors 2i of the deectorhousing l' break up the air from the fan wheel into laminations. -Theair forced by the fans into the passenger space builds up a pressurewithin the car and this forces the air in the passenger space throughthe ceiling outlets into the space between the roof 8 and ceiling l andover and in contact with the ducts 6 and then through the roof outlets"i8 into the atmosphere. n

By arranging the ceiling outlets l1 at the ends of the car and the roofoutlets I8 near the center 'of the car, the entire space between theceiling and roof is continuously ventilated to prevent the accumulationof heat. l

By arranging the centrifugal fan wheels below the ceiling of the car,they are enabled to force the air most efficiently inall directions inthe substantially horizontal streams desired. lAs a lresult higheiciency is obtained together with the movement of large volumes of airthrough the passenger space which effectively cools the passengerswithout drafts.

Preferred results are obtained when the air in the car is changed atleast once every minute. In the embodiment illustrated, each fan removes800 cubic feet per minute resulting in a total movement of 4,000 cubicfeet per minute through a car having a capacity of 3,900 cubic feet. Theair leaves the fans at a velocity of about '700 feet per minute, yetsince the air is directed into ithe car in substantially horizontalstreams, the large volumes of high velocity air produce no drafts orother unpleasant eiects upon the passengers.

While one embodiment of the invention has been described for the purposeof illustration, it should be understood that the invention is` notlimited to the exact apparatus and arrangement of apparatus illustratedand described, since many departures may be suggested by those skilledin the art, without departing from the spirit of the invention.

What is claimed is:

1. A pressure Ventilating system for a railway passenger car havingaceiling and a roof above the ceiling, comprising a plurality oflongitudinally spaced fans communicating through the ceiling with thepassenger space, means forming air passages in the space between saidceiling and roof, connecting said fans with outdoor air, and meansincluding vitiated air inlets in'said ceiling between the ends of thecar and the. outermost of said fans, and vitiated air outlets -to theatmosphere in the space between said ceiling and roof adjacent thecenter of said car for passing vitiated air in contact with theexterior' of said passages and for then discharging it from saidv car.

2. A pressure Ventilating system for a railway passenger car having aceiling and a roof above the ceiling, comprising a plurality oftransverse ducts having inlets communicating through thel teriors ofsaid ducts and for then discharging it from said car. i

3. A pressure Ventilating system for a railway passenger car having aceiling and a roof above the ceiling, comprising va plurality oftransverse ducts having inlets communicating `through the sides or^ saidcar with outdoorair and having outlets communicating through saidceiling with the interior of said car, said ducts having their upperwalls spaced from said roof to form air `passages therebetween, fans insaid outlets for drawing air through said inlets for supply into saidinterior,r and means including vitiated air inlets in saidceilingbetween each end of said car andthe outermost of said fans, andvitiated air discharge outlets communicating with the space betweenrsaid ceiling and roof adjacent the center of said car for passingvitiated air from the interior of said car over said ducts and for thendischarging it from said car. l

' CARLO. BERGSTROM.

